Active medical devices for delivering stimulation therapy to body organs such as the heart, brain, or other tissues are typically comprised of two major components. One component is an electronic circuit and power source, typically a battery, housed in a hermetically sealed container, often referred to as the implantable pulse generator (IPG), or as the “can”. The container includes feed-throughs allowing electrical signals and power to pass through the hermetic containment in and out of the circuitry to the second major component, the lead. This lead carries electrical signals from the IPG to the target body tissue in order to deliver therapy. The lead may also house conductors that carry signals generated by the human body back to the IPG.
The conductors within the lead are exposed at electrode sites on the distal end of the lead and interface by direct contact with body tissues. At the proximal end of the lead, the conductors are again exposed. Various forms of metallic rings, or segments, or end protruding pins are used to make the conductors available at the outer surface of the lead. The proximal end of the lead is inserted into the receptacle of the IPG and the lead's conductors are aligned with mating conductive surfaces inside the receptacle.
For the interconnection of the lead and the IPG it is essential that the exposed conductive surfaces on the lead to align with the conductive surfaces in the receptacle of the IPG. This alignment is accomplished at the time the medical device system is implanted by the implanting medical personnel. There may be one or a plurality of leads to be inserted and correctly aligned, and the environment in the surgical arena makes it difficult for the implanting medical personnel to be sure each lead is fully and functionally inserted, before leaving the medical device in the patient's body and closing the surgical wound.